Why did the Qin not attempt their unification before Ying Zheng?(for example under Duke Xiao or King Zhaoxiang) Did they just not have the resources?

I can’t find any information on this topic. I was wondering if they even did take anything considering there were plenty of extremely important artifacts shipped to Taiwan by the KMT during the civil war. But you rarely hear about invading forces not looting anything. Artifacts including books and arts

This is a follow-up to my last post on this sub. I want to go through each major Chinese era/dynasty from the Western Zhou to the Qing and ask the community who their favourite ruler is from that time period. I purposefully use the word favourite, so it doesn't have to be the best, the worst, the most interesting or most well-known, but rather who you personally view as your favourite. This time I want to emphasize that I don't just want you to write down a name, but provide explanation on why you like them too.
The upcoming eras are going to be: Han, Three Kingdoms period, Sima Jin (including the Sixteen Kingdoms), Northern and Southern dynasties period, Sui, Tang, Five Dynasties and Ten Kingdoms period, Song, Liao, Jurchen Jin, Yuan, Ming and Qing. These categories may be subject to change because I know this categorization is dated but its the best I've got.
So in this post I want to read about your favourite rulers from the Qin and the Han dynasty meaning from the establishment of the Qin dynasty to the last Han emperor abdicated. This also includes Wang Mang and the Xin dynasty. I'm not making a separate post for the QIn dynasty, since there aren't many emperors to talk about. This time however I'm only including the emperors themselves, so the warlords that emerged during the Yellow Turban Rebellion and the Five Pecks of Rice Rebellion are NOT included (they will be the subject of the next post). Rulers of the so called Eighteen Kingdoms ARE included however, who emerged after the fall of the Qin dynasty (tho I doubt anyone will pick them).
I also want to thank all the comments and discussions under the last post, I will try to improve future posts according to your suggestions.
Picture are from the Qin dynasty and the Timeline of the Han dynasty wikipedia pages respectively.

What is a better translation?